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61.
ABSTRACT: Color of natural waters strongly influences their aesthetic appeal, suitability for recreational use, and aquatic habitat, but methods for routine specification of color have been lacking. An improved method has been developed for specifying water colors in the field. The water color, seen through an underwater viewer, is matched directly to Munsell standard patches observed simultaneously. The Munsell color-matching method was verified versus measurements of the underwater light field, made with a submersible spectroradiometer in 20 different natural waters in New Zealand (mainly lakes), which varied widely in color and other optical characteristics. Hue, the most important color attribute of natural waters, could be matched accurately; the saturation and brightness less so. Color standard patches are not available covering the full range of typically dark water colors, but fortunately, brightness can be measured with simple submersible light sensors. The Munsell color matching method seems suitable for routine water resources survey and monitoring.  相似文献   
62.
ABSTRACT: The solution of a water resource allocation problem by an alternative social arrangement is presented. Classical Austrian economic theory and the “new resources economics” provide both theoretical and practical evidence to support the development of well-defined, private property rights to the water resource in question. A conflict analysis demonstrates that management of the Manayunk Canal by a firm would reconcile existing confrontations through compromise use of the water resource. Benefit and cost calculations show that a compromise among industrial and recreational interests, currently competing in the political arena, would increase social benefits.  相似文献   
63.
Utilizing an adaptation of the Universal Soil Loss Equation, this article discusses a method for approximating the physical carrying capacity of natural areas for outdoor recreation. Classification of forested woodland and field environments is based upon the conversion of ground cover coefficients to the percentage of ground cover required to maintain soil productivity over time. Four canopy types, three canopy densities, and two general types of ground cover are recognized in the equation as well as soil characteristics, topographical variations, and rainfall velocities and intensities. The method requires that the areal distribution of soils occurring within natural areas be mapped. Approximations will vary according to the intensity of the planning desired, and may range from a general classification of large land areas to highly site-specific evaluations. Data generated from over 40 years of cooperative research form the basis for classifying natural areas according to their relative physical capacities to accommodate outdoor recreation.  相似文献   
64.
ABSTRACT: The Chubb/Bauman (Ch/B) method for making quantitative estimates of recreation potential for rivers is based on the 1968/ 69 Leopold method for quantitative assessment of the scenic beauty of rivers. Both use classifications of environmental variables as the database. Unlike the Leopold method, the classifications used in the Ch/B method consistently reflect human preferences. The Ch/B method collects information on 67 variables, and uses a computer program to produce estimates of potential for 16 common recreation activities. This critique evaluates selected concepts and procedures of the Ch/B method partly by comparison with other available methods of recreation resource inventory. It considers the validity and utility of numerical weighting of variables, the use of numbers derived from place in a classification, and the transformation process. The quantitative techniques of the method exhibit serious flaws. Much of the data produced by the method appears to be quantitative but in fact is not, and it does not produce truly quantitative estimates of recreation potential. Classifications of generalized geographic or environmental variables are shown to have serious defects as a basis for evaluation of recreational potential.  相似文献   
65.
Although the volume of potable water used at recreation developments is minor relative to total regional water use, very high quality is required and the source is often of limited capacity, such as a mountain spring or small local aquifer. Frequent confrontations between developers and regulatory agencies result from claims by developers that water demand will be very small while regulators tend to treat such developments the same as municipal residence. Almost no published data base exists for resolving such conflicts. Included here are: 1) Water use measurements of various peak period durations (seasonal, monthly, daily, and instantaneous) at several types of recreational developments in Utah and Wyoming (mountain cabins, both ski- and water-based condominiums, and recreation vehicle campgrounds), 2) statistical (frequency) analysis of the data and a comparison with municipal demands in the same region, and 3) analysis of occupancy rates at the various categories of developments.  相似文献   
66.
The estimation of the value of recreation benefits resulting from improved water quality is required for many purposes. In particular, the Water Pollution Control Act of 1980 requires the consideration of the reasonableness of costs of reducing water pollution in relation to benefits to be derived from establishing effluent standards (Clean Water Act of 1977). Recreation is often the most important benefit resulting from water quality improvement. Current methods used to calculate recreation benefits are either not site-specific or are expensive and controversial. This paper presents a relatively simple, inexpensive, and less controversial method of calculating site-specific recreation benefits resulting from improved water quality. It does this by producing an upper bound estimate which often is adequate for the relevant decision. The upper bound estimates is based on two assumptions: 1) there are alternative equivalent substitute sites for the newly augmented water quality site, and 2) the new augmented recreation opportunities at the site will be used to their maximum supply capacity. Clearly, if an upper bound benefit estimate in a cost-benefit ratio does not produce a favorable ratio, no other benefit estimate will. In cases where this estimate produces an ambiguous result resort must be had to other more precise methods of estimation.  相似文献   
67.
Considerable attention has been devoted to the concerns and perceptions of people residing around contaminated facilities, both brownfields in urban areas and others located in remote and lightly populated areas. This paper examines the concerns of recreationists and sportsmen residing near the Department of Energys (DOE) Brookhaven National Laboratory, in central Long Island, one of the most densely populated regions in the United States, where tourism is of prime importance. On an open-ended question, the greatest concern was pollution, followed by environmental health as a global concern, and human health as a concern for Brookhaven. Accidents/spills, loss of public health, and loss of ecological health were rated highest among a list of concerns, and change in property values was rated lowest. When asked to rank seven concerns, protecting human health was ranked the highest, and economic interests were ranked the lowest. For future land use at Brookhaven, recreational uses were rated the highest, while building houses and factories, and storage of nuclear material were rated the lowest. These data can be used by managers, decision and policy makers, and the general public to assess and manage local and regional environmental concerns and to consider future land uses for decommissioned lands, such as those at Brookhaven.  相似文献   
68.
Air pollution has been identified as a serious problem throughout the world which causes tremendous loss to the crops by affecting plant growth and yield. Earlier, air pollution was restricted to urban and industrial regions. Over the last few decades, however, it has become evident that pollutants can be transported over long distances and hence their impact may be felt widely over rural areas. The present study was conducted to evaluate the impact of urban air pollution on suburban agriculture with respect to the changes in photosynthetic rate, stomatal conductance, water-use efficiency, plant height, numbers of tillers, leaves, ears and seeds, chlorophyll, carotenoid, protein, phenol, ascorbic acid, nitrogen and sulphate-sulphur contents and seed weight of pot-grown wheat plants (Triticum aestivum var. HUW 468) kept at different sites around Varanasi city receiving varying levels of pollution load. Mean concentrations of were monitored. The study clearly showed that plants are negatively affected by the ambient levels of air pollutants. Reduction in various parameters directly corresponded with the air pollution levels at different sites.  相似文献   
69.
Airborne particulate matter (PM) concentrations were measured in Iksan, a suburban area in South Korea during April, 2003. PM2.5 (particles with an aerodynamic diameter less than 2.5 μm) and PM10 (particles with an aerodynamic diameter less than 10 μm) samples were collected, and the chemical characteristics of particles were examined for diurnal patterns, yellow dust/rainfall influences, and scavenging effects. Average concentrations of PM2.5 and PM10 mass measured were 37.3 ± 16.2 μg m−3 and 60.8 ± 29.5 μg m−3, respectively. The sum of ionic chemical species concentrations for PM2.5 and PM10 was 16.9 ± 7.3 and 23.1 ± 10.1 μg/m3, respectively. A significant reduction in PM mass concentrations during rainfall days was observed for coarse mode (PM2.5 − 10) particles, but less reduction was found for fine (PM2.5) mass concentration. SO4 2−, NH4 +, and K+ predominated in fine particulate mode, NO3 and Cl predominated in fine particle mode and coarse particle mode, but Na+, Mg2+, and Ca2+ mostly existed in coarse mode. The high concentration of ammonium due to local emissions and long-range transport neutralized sulfate and nitrate to ammonium sulfate and ammonium nitrate, which were major forms of airborne PM in Iksan. Average mass concentrations of PM10 in daytime and at night were 57.6 and 70.0 μg m−3, and those of PM2.5 were 35.4 and 42.5 μg m−3, respectively. NO3 and Cl in both PM2.5 and PM10 were about double at night than in the daytime, while the rest of the chemical species were equal or a little higher at night than in the daytime. The results suggest the formation of ammonium nitrate and chloride when high ammonia concentration and low air temperature are allowed. Backward air trajectory analyses showed that air masses arriving at the site during yellow dust period were transported from arid Chinese regions, which resulted in high concentrations of airborne PM mass concentrations. In the meantime, air mass trajectories during a rainfall period were mostly from the Pacific Ocean or the East China Sea, along with a relatively low PM concentration.  相似文献   
70.
After 50 years of steady increase, per capita visits to US national parks have declined since 1988. This decline, coincident with the rise in electronic entertainment media, may represent a shift in recreation choices with broader implications for the value placed on biodiversity conservation and environmentally responsible behavior. We compared the decline in per capita visits with a set of indicators representing alternate recreation choices and constraints. The Spearman correlation analyses found this decline in NPV to be significantly negatively correlated with several electronic entertainment indicators: hours of television, (rs=-0.743, P<0.001), video games (rs=-0.773, P<0.001), home movies (rs=-0.788, P<0.001), theatre attendance (rs=-0.587, P<0.025) and internet use (rs=-0.783, P<0.001). There were also significant negative correlations with oil prices (rs=-0.547, P<0.025), foreign travel (rs=-0.452, P<0.05), and Appalachian Trail hikers (rs=-0.785, P<0.001). Income was significantly positively correlated with foreign travel (rs=0.621, P<0.005) but negatively correlated with national park visits (rs=-0.697, P<0.005). There was no significant correlation of mean number of vacation days, indicating available vacation time is probably not a factor. Federal funding actually increased during this period, and so was rejected as a probable factor. Park capacity was rejected as limiting since both total overnight stays and visits at the seven most popular parks rose well into the mid-1990s. Aging of baby boomers was also rejected as they are only now reaching retirement age, and thus during the period of visitation decline were still of prime family vacation age. Multiple linear regression of four of the entertainment media variables as well as oil prices explains 97.5% of this recent decline (r=0.975, multiple r2=0.950, adjusted multiple r2=0.925, SE=0.015, F=37.800, P<0.0001). We may be seeing evidence of a fundamental shift away from people's appreciation of nature (biophilia, Wilson 1984) to 'videophilia,' which we here define as "the new human tendency to focus on sedentary activities involving electronic media." Such a shift would not bode well for the future of biodiversity conservation.  相似文献   
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